Emergency lighting unit with integrated electronic ballast

The invention relates to an electronic circuit to be used in a self-contained emergency lighting in maintained mode, comprising an AC/DC input converter (1), a DC/DC converter (3), an electronic ballast (5) and an electronic control circuit (4). The electronic circuit is characterised in that the electronic control circuit (4) supervises the low volt input DC voltage (LVDC) and/or the battery current to recognise a failure of the direct mains input (DPH) and in consequence to switch from normal mode to emergency mode and to control the high voltage DC voltage (HVDC) of the electronic ballast (5) in the emergency mode in order to adjust the output power of the lamp (6) in the emergency mode to the needed requirement.